rude consultant

i got a call from a guy from this company a day ago and i confirmed with him that i will be making a payment on the last day of the month. he confirmed it was okay and noted my arrangement down and sent me banking details. today i get a call from a lady saying that i need to do a debit order today because i cant do an eft. i asked her why and she gave me a stupid explanation saying i just have to do a debit order. i said if you debit my account today, there is no funds there, so whats the use of doing the debit order. she said i need to go and get money today and deposit it. where can i pull the money from? a tree? im handed over because i couldn't afford the account an now i made an arrangement to pay but you want to dictate? terrible Service!!!